How Do Changes in Ecosystem Quality Drive the Potential for Soil Organic Carbon Sequestration in High‐Altitude Areas?

ABSTRACT Climate change and ongoing soil degradation are eroding terrestrial carbon sinks, underscoring the need to understand how ecological environmental quality changes (EEQC) shape soil organic carbon (SOC) functions. Prior work has often overlooked regional sensitivity in EEQC and provided limited evidence on how EEQC drives SOC storage (SOCS) and SOC sequestration potential (SOCSP). An EEQC evaluation framework was introduced in this study that incorporated vulnerability and regional sensitivity in pressure and status indicators, accounted for landscape configuration, human activities, and natural context, and revealed the spatiotemporal characteristics of EEQC in Qinghai Province (QH). We further used the soil carbon saturation deficit to assess SOCS and SOCSP, and applied geographically weighted regression and structural equation modeling to examine spatial correlations and causal pathways. Analyses focus on the 0–30 cm soil layer for 1990–2020. EEQC improved markedly over the study period with pronounced spatial variability: the greatest gains occurred in eastern and central QH where restoration efforts were concentrated, while the Qaidam Basin showed limited improvement constrained by natural conditions. Spatial diagnostics show higher historical SOCS in central and southeastern QH, commonly 50–70 or > 90 Mg C·hm −2 , and lower values < 30 Mg C·hm −2 in the Qaidam Basin. In low‐saturation zones, restoration delayed saturation and increased SOCS; in high‐saturation areas, limited input capacity constrained SOCSP. Status indicators had a direct positive effect on SOCS with coefficient = 0.38 and on SOCSP with 0.19, whereas pressure indicators had significant negative effects of −0.26 on SOCS and −0.27 on SOCSP and also suppressed status improvements. This study enhances the understanding of spatially explicit relationships between EEQC and SOCS/SOCSP, offering a robust framework for optimizing ecosystem restoration and carbon management strategies. It provides valuable scientific guidance for addressing the dual challenges of achieving regional carbon neutrality and improving ecological resilience under complex environmental conditions.